ammonia alum vs Al

ammonia alum and Al both are nouns.

Word	Noun	Adjective	Verb	Adverb
ammonia alum	Yes	No	No	No
Al	Yes	No	No	No

As nouns, Al is a hypernym of ammonia alum; that is, Al is a word with a broader meaning than ammonia alum:

ammonia alum: a white crystalline double sulfate of aluminum: the ammonium double sulfate of aluminum
Al: a silvery ductile metallic element found primarily in bauxite

Other hypernyms of ammonia alum include aluminium, aluminum, atomic number 13, double salt.

ammonia alum (noun)	Al (noun)
a white crystalline double sulfate of aluminum: the ammonium double sulfate of aluminum	a silvery ductile metallic element found primarily in bauxite